Thresher with adjustable speed cylinder drive



Jan. 27, 1948. 7 c SCRANTON 2,435,020

THRESHER WITH ADJUSTABLE SPEED CYLINDER DRIVE Filed May a, 1941 2Sheets-Sheet 1 Jan. 27, 1948. c. J. SCRANTON 2,435,020

THRESHER WITH ADJUSTABLE SPEED CYLINDER DRIVE Filed May 8, 1941 2Sheets-Sheet 2 Patented Jan. 27, 1948 THRESHER WITH ADJUSTABLE SPEEDCYLINDER DRIVE Charles J. Scranton, La Porte, Ind., assignor toAllis-Chalmers Manufacturing Company, Milwaukee, Wis., a corporation ofDelaware Application May 8, 1941, Serial No. 392,469

2 Claims. 1

This invention relates in general to the operation of threshing and likemachines under variable speed conditions; and the invention isparticularly concerned with the provision of a threshing machine of theharvester-thresher type equipped with a variable speed threshingcylinder drive affording a wide variation in operating speeds of thecylinder.

In the operation of threshing machines, especially modern machines ofthe harvesterthresher type, it becomes desirable, in the interest ofinsuring efiicient threshing operation, to operate the threshingcylinder at different speeds, depending upon the particular crop beingharvested, and other conditions, such as moisture in or adhering to thematerial harvested and the volume of straw to be handled by the machine.And the most desirable operating speed of the threshing cylinder of amodern harvesterthresher, to effectively and efiiciently take care ofdifferent crops and under difierent conditions thereof, might vary fromapproximately 425 R. P. M. to approximately 1700 R. P. M. And thepresent invention contemplates the provision of a threshing machinehaving a variable speed cylinder drive, of specialutility in connectionwith a harvester-thresher, which provides in a simple manner for a verywide variation in the operatin speed of the threshing cylinder and isreadily adjustable, even with the machine in operation, to secure anydesired cylinder speed. And the invention contemplates such anassociation of the drive and its adjusting means with the'threshingmachine as will permit adjustment of speed of the threshing cylinderfrom a position wherein adjustment-by an operatorinvolves little or nodanger from moving parts of the machine.

It is an object of the present invention to provide an improved andefficient variable speed cylinder drive for a threshing machine,affording a wide range of operating speeds and readily adjustable durinoperation of the machine.

It is a further object of this invention to provide a threshing machineequipped with a variable speed threshing cylinder drive of improveddesign and construction and interrelation to the parts of the threshingmachine.

It is a further object of this invention to provide a threshing machineof the harvesterthresher type equipped with a variable speed threshingcylinder drive of improved design and construction and interrelation tothe parts of the machine, and providing for a wide variation inthe'operating speed of the threshing cylinder and adjustable by anoperator, during operation of the machine, from a readily accessibleposition with minimum liability to injury through contact with movingparts of the machine.

These and other objects and advantages are attained by the presentinvention, various novel features of which will be apparent from thedescription and drawings, disclosing an embodiment of the invention, andwill be more particularly pointed out in the annexed claims.

In the accompanying drawings:

Fig. 1 is a view in side elevation, with parts to the left of thevertical planes of the line 1-1 of Fig. 2 omitted, of aharvester-thresher of a conventional modern design and embodyingfeatures of the present invention;

Fig. 2 is a view in front elevation of the apparatus shown in Fig. 1,with the header platform and other parts omitted;

Figs. 3 and 4 are enlarged vertical section-a1 and side elevationalviews, respectively, of a detail concerned with the adjusting mechanismof the variable speed cylinder drive of the machine of Figs, 1 and 2,the plane of section of Fig. 3 bein that of the line III-III of Fig. 4;

Figs. 5 and 6 are enlarged front elevations, with parts in section, ofdetails of the cylinder drive, the plane of section of Fig. 6, beingthat of the line VIVI of Fig. 7;

Fig. '7 is a side elevation of parts shown in Fig. 6;

Figs. 8 and 9 are vertical sectional views, in the plane of the lineVIII-VIII of Fig. 1, showing the driving sheave in alternativeconditions of operation; and

Figs. 10 and 11 are diagrammatic views indicating two differentoperating conditions of the variable speed drive.

As indicated in Figs. 1 and 2 of the drawings, supporting wheels 5 and6, mounted at the stubbleward and grainward sides, respectively, of alaterally extending axle I, serve to support a harvester-thresher, thesupporting frame structure F of the machine being mounted on the axle.This frame structure includes a forwardly extending draft frame portion8, at the stubbleward side of the machine, the draft frame comprising alongitudinally extending frame bar 9 mounted on the axle near the endthereof and projecting rearwardly of the axle and forwardly thereof, anda second frame bar In mounted on the axle and extending rearwardlythereof and also extending forwardly in a general longitudinaldirection, but inclined toward the frame bar 9 and connected theretonear the forward end thereof. Generally longitudinal frame bars l2 andI3, lying in the vertical planes of the frame bars 9 and I0,respectively, are inclined downwardly and united with the latter framebars adjacent the forward end thereof. The rear ends of the frame barsl2 and I3 are secured to vertical supporting? bar's Hi-- and" "I5;' resperitively;- v

mountedcnthe frame bars 9 and m; respectively? forwardly of the axle l,

A housing I1 is mounted on the frame struts-+- ture F at the grainwardside of-the-machine,=.the

housing bein supported in partby a'liorizontal' frame bar I 9 carried byvertical supports 21, with the front open end of the housing llprojecting forwardly of the aXle I and beinglaterally'spaced from thedraft frame 8. At the'forward open seedfrom-thastalks; and the straw orstalks and end of the housing [1, a conventional header: j

platform 23, through the side walls thereon, is

pivotally mounted at its upper rear endwitfftlie" side walls of theheader projecting into the open forward-end of the-housingl llEhelheader platform :is provided with-a-conveyer belt 24 preferably ofconventional drapertype, for carrying materiaLharvested by a sickle attlie lower forward end of the platform, to the: thre'sherhousing; Theaxis of the upper roller, indicated at 25, of the feed -dra ner 24preferably coincideswith' the pivotal axis of the' side walls of theheader on the housing l'l.-

Within the thresher housing b7; at -apoint rearwardly of' the rear endof the conveying draperiil t is mounted a threshing cylinder 26 havinghis shaft 21 rotatable in bearings 2'8 carried by the side-walls 'of thehousing H. The threshing cylinder is preferablyof heretofore known openbar type and cooper'ates with a stationary concave 30 mounted in thehousing 4 1 beneath the cylinder; a forwardly projecting portion of theconcavereceiving-material from the discharge end-of the feed 'draper 24The stubblewardend ofthe cylinder shaft fl; beyond the housing 1-1,- is-provided with" a V groove sheave '32 of adjustablei type 't'o bedescribed morein=detail hereinafter.- And a V-belt 34 passing about adrivi1ig-sheave 35described more in detail hereina'fter, onthe shaft 35'serves to drive the cylinder: shaft 21 "at a sp'eed deter mined by thespeed of: theshaft -SE and th'e .relation between the pitch ldiami'eters of-s1ieaves 32 and 35i Power is supplied to the driving shaft 36mm: a longitudinal drive shaft' 39 h'aving flexibly 'c'onne'ct'edportions andsuitably 'supportedatiitslrear endina bearingprovided inaatransmissionzhous ing 4! carried by a platform dzmounted onathe lowerlongitudinal frame; bars 9 and of the draft frameB and the frontendoftlie drive shaft 39 is supported in conventionalimanner in ago-1aable bearing carried-by: andi ad iacentrtheiforward end of thedraftzframe, the: forward' 'endlot-this drive shaft being, provided'withz conventional means for connection to'i a-rpower takeoff 7on1 thetractor engina- A suitable gearrconnection, referred to hereinafter,between: the rear end of the drive shaft 39 and.:the' stubblewardiaendiof the shaft-36 is providedwithiii'theltransmission housing 41forLdriving the shaft: 36LII'0II1I17HG drive shaft 39.

When the harvester=thresher1 iszdrawnrthrough a field by a tractor, withthe-latteriop'eratingithe drive shaft 39 carriedv by tlrre draftframe;the various conventional: operating mechanismsbf the harvester-thresher,such as the: harvesting sickle; the threshingaoylinder;.thevseparatingand cleaning.mechanismzandctheinecessarytelevators;

threshed' grain are forced out rearwardly and upwardly from the spacebetween the cylinder -and' theconcave -into the separating mechanism153:

bleseparatingaction thereon, the straw is disd'isposedtotherea'r-of thecylinder. After suitacharged from thetapparatus, and the grain recoveredthrough the separating action, is conveyed; preferably after a furtherconventional cleaning action, and discharged to a receiving bin Rsuitably mounted? on the 'supportingframe structurel What.mightbaasatisfactoryrand efficient operating speed of the threshing cylinderwhen threshing-:thoroughly' .dry grain orx'the like; aswhemoperatingtaiharvesterthresherduringg'the' middle: of a bright .day,would not ibesatisfactory or efiicient when threshingzgrainxorlthelike:under somewhatdamporother conditions; and to accommodate: for sueh'ivariable: conditions, .a simple 1 and readily-operated: device: isprovided,- through which the speedof ithethreshing cylinder: can bereadily adjusted: over 'ai-wide range with full safety to the operatorsduring: the necessary adjustments.

.It is pommonimnodern tractorsdrawniharvester= threshers "to concentrate-:as 1 much: of ithermain drive elements; .irrcluding-;thet sheaves,similar to thesheaves Hand-:35 between-the grainward: side ofthethreslier:housingandiantofiset draitaframe; such as' indicatedtat '8;This' is -3f-pi0SltiOI1 WhiCh not readily ac'cessible': to an operatorwithout climbing. or leaning Jon iorrover the 1: drafts-frame; andfituisa position whereinitheoperator is very likely; to be'zinjurediwhen thectraoton engine is drivingwthe operating mechanisms: ofthe:harvester-thres'herg, even though the tractor and harvester threshenare: stationary; at: the; time. An'd'since: it is veryidesirablefor; an:operatorrtozbe able mos-accurately determine the: speed ofz'thethreshing; cylinderrwhile 'he isvmaking adjustments ofsuch;speed;fitbecomesfihighhi desirable that the:spee'd ofztliethreshingicylinder' be-capable. of: being readily; varied -from 1 apoint where them eratorfcan "b'eisafe; evenwth'ough the=threshing"cylinderfand other iparts' of the machine :are in operation;and-sitris-z likewisewhighlyl desirable that the operator, in such asafe position, be:ab1e to: maketachometer readings of: the: cylinderspeed atzthe: sametime he is changing. such speed: These effects'arewaccomplished through 1' provi sions hereinafter described;

Sheave 32: on the rcylinder shaft 21 l iscompo'sed of twooutwardlyIla-ringside walls iii-and having "hub portions and: 48; respectively,integral with ornattached i thereto and theside wall 45 is heldrfixedrelative: to the'sh'aft: 2 1-: by having its hub portion f01Cd-'.3Zi'1dheld'-b3b'anuti 49 on a tapered endiof theshaftr And the- 111111)portion 48. of the side-wall M3 isprovided with a sleeve portion ateextendingl-inwardlyf :toward the wall of the housing I l this:hubportion 48; iwithwits :sleeve 50', being; splined-ron sth'eshaft 21.soias: to ;provide for "rotation of. the: side zwalls ifir with: the: Ishaft while' permitting-1 axial movement toward and from the side wall45, to vary the effective pitch diameter of. the sheave. Insuranceagainst relative rotation between the side walls 45 and 46 of the sheaveis provided through a plurality of spaced axially extending pins orbolts 52,secured to the hub 48 and passing, with a guiding fit, intocorresponding spaced apertures 53 in the hub portion 41 of the side wall45.

The side Wall 46 may be adjusted to desired position with respect to theside wall 45 to provide a V-groove sheave of desired effective pitchdiameter for the v driving belt 34, by means of an adjusting collar 56mounted upon the sleeve 56 of the hub portion of the side wall 46 insuch a manner as permits rotation of the sleeve portion within thecollar and also permits axial movement of the sleeve portion along withthe collar. A suitable arrangement is one wherein a ball bearing 51 isprovided between the sleeve portion 50 and the collar 56, the inner raceof this ball bearing being held in fixed position on the sleeve and theouter race being held in fixed position within the collar. An actuatinglever 59, pivoted intermediate its ends to a fixed portion of theapparatus, such as a projection on the outer portion of the adjacentbearing 28 of the cylinder shaft, has its upper end of conventionalclevis formation with the arms, indicated at 6|, embracing oppositesides of the collar, the upper end. of each such arm being slotted toreceive a pin 62 projecting from the side of the collar 56.

The sheave adjusting lever 59 is operated by an actuating rod 64 havingits stubbleward end pivotally secured to th depending lower portion ofthe lever 59. This actuating rod passes through an aperture in theadjacent portion of the stubbleward side wall of the housing I! andextends laterally through the housing, beneath the concav 38, definingthe lower wall of the active threshing chamber. The opposite end of therod 64 is in threaded engagement with interior threads formed within ahollow stud portion 61 of an actuating element 63 having an actuatingcrank 69. This actuating element is held in operative position, with thehollow stud portion thereof passing through and rotatably mounted in anaperture in the grainward side wall of the housing I1, with a guidingfit in a bearing element, in the form of an apertured plate 12 removablymounted on the outer side wall of the housing ll. The outer head portionof the actuating element is provided with an external flange providingan abutment shoulder 13 bearing directly, or through the intermediate ofa washer, against the outer face of the bearing plate 12.

The spreading action of the belt 36 in the groove of the sheave 32against the side wall 46 thereof maybe relied on to hold the actuatingelement drawn into firm frictional engagement against the outer face ofthe .bearing plate 12; or the bearing plate may be formed in separateupper and lower sections entering an annular groove in the periphery ofthe stud portion 61 to thereby positively hold the actuating elementagainst axial movement relative to the side wall of the housing, whilepermitting rotation of the actuating element. A nut 15, locked inpredetermined position on th rod 64, serves, through engagement with theinner end of the stud portion 6"! of the actuating element, to limit thedegree to which the side wall 46 of the sheave 32 may be forced towardthe side wall 45 thereof. If it should be desired to limit theseparation of the side wall 46 of the sheave from the side wall 45thereof to a degree'less than that provided by engagement of the sleeveportion 58 of the side wall 46 and the collar 56 with the adjacent faceof the stubbleward bearing 28, a lock nut similar to that indicated at15, may be provided on the outer end of the rod 56 for engagement withan internal abutment shoulder 16 on the hollow stud portion 61 of theactuating element. While the crowding action of the belt 34 against theside wall 46 of the sheave 32 may be sufficient to frictionally hold theactuating element in adjusted position, this effect may be supplementedwith a conventional form of latching device associated with theactuating element and the bearing plate 12.

A supporting bracket 18 is secured in position on the supportingstructure of the harvesterthresher, below the forwardly projecting endof the housing l1, this bracket being mounted in position throughhanging bolts 19 alone, secured to the'frame bar 19, or in conjunctionwith one or more supplemental bracing brackets 88, whose rear end issecured through a bolt 79 and whose forward end is suitably secured to aportion of the frame structure. The supporting bracket 18 is providedwith side walls 8|, 82 having alined apertures, the aperture in the sidewall 82 being considerably larger than the aperture in the side wall 8|.Within the aperture in the side Wall 82, an element 83 is mounted forguided rotation through the Wall of the aperture, this element beingcentrally apertured and having a peripheral flange at its inner end anda ratchet surface at its opposite end projecting beyond the side wall ofthe bracket.

A rod or shaft 85 passes through the aperture in the side wall 8| andthrough the aperture in the ratchet element 83, this shaft beingsupported in position by and extending laterally beyond the supportingparts, and being suitably held against appreciable axial movement. Anidler pulley 86 is rotatably mounted upon the end of th shaft 65extending beyond the side wall 8| of the supporting bracket. A secondidler pulley 8! is rotatably mounted on a, stud shaft or bolt 89extending laterally from the lower end of a supporting hanger or bracket90 whose upper nd is rotatably hung on the shaft 85 in such a mannerthat the hanger may swing or oscillate on the shaft 85. The pulleys 86and 81 are disposed in a vertical plane which substantially coincideswith the plane of the pulleys 32 and 35.

As indicated in Figs. 10 and 11, the idler pulley 86 bears On the outersurface of the belt 34 under all conditions of variable adjustment ofthe drive, and the idler 81 may be caused to bear on the inner surfaceof the belt with such varying degree of pressure as to cause the lowercourse of the belt to assume the necessary distortion to assure firmdriving contact with the walls of the adjustable sheave 32 in itsvarious conditions of adjustment. A torsion spring 92 surrounds thatportion of the shaft 85 between the bracket 90 and the ratchet member8.3, being spaced from the shaft by a separating sleeve 93. One end ofthe spring 92 is secured to the bracket 90 and the other end of thespring is secured to the ratchet element 83, this connection preferablybeing made by inserting the extending end ofthe spring into a selectedone of a plurality of apertures 94 in the flange portion of the ratchetelement.

A ratchet operating head 95 surrounds the grainward end of the shaft 85and is provided with ratchet teeth for coaction with th ratchet teeth ofthe element 83, the teeth on the rachet lieadrfl beingibiaseuiiintoengagement witli athe teetlmnitliaratchet element BQby RTCOmPrBSSMX-Tspring 96: surrounding: the shaft and fbearnig againstthematchet-iheadaandia collarrslisecured tothef shaft; Theratchetiheadlistprovidedlwith an"operating handlest; through wliienlitrmay be actuated to rota'te. 'the ratchet element through theratchetconnection between these parts; so as toapply'itherequirewtorsionalistrain' omthe: spring 92 to cause it to mge'the hanger 911 .to: a position"- wherein 1: thenidler 131 F serves-"to"place the: required tension on the" driving: belt 34-; During adjustmentoffithe- Itorsionalstrain on the spring 92, a holdingilateh' NH,pi-votallymounted on the end wall a 82 i the-- supporting bracket; maybe released irom holding engage ment with a cooperative :series ofnotches fl {won the periphery oizthe flanged portion 'of Ltherratche-telement 83-. The 'torsion of the spring' si mm be adjustedinitiallydthroug-h the ratchet-device; so' to cause the idlerral ntobear: with the required degree of pressui'e 'on the innersurface of thebelt 34; to thereby produ'ce'asatisfactory degree: of tension thereonifor eflicient driving of the'adjustable sheave 32lthroughoutits'fullrange of adjustmentaor pltch diameter.

As :indicated in Fig; 8, the pulley 'fli is made up 01 a centrallyaperturedi-hub 'li33 through which the: sheaveis secured on' the shaft3B; the hub being'eprovided with a peripheral fiange' l 04 mm which alongitudinally extending circular "flange lfl5 projects: The side wallsHlfi-and I ll! ofthe sheave, inclinedi away from each othertoward theperiphery, are secured il'I-DGSitiOn on the flange l 04: through theintermediary of aspacer ring 'lml disposed between the= flange H35- onthe hub and the innerportion-of thesidewalr lilb; and a spacer ring I l09 between theiradiallyinner portion of the side wall MIT and an annularclamping plate H3. Clamping boltslitj passing: through :alinedaperturesin the side walls I881 I013 the spacer rings [08, I'DQ- andtheclamping plate I I3; serve to hold the parts in assembled re; lation.This relative arrangement o'fi'the-side walls of the sheave --and-thesp'aeer rings 1118, 109; shown in Fig.- 8, will produce a sheave of aneffective pitch diameter for operation of the belt 34 that is onlyslig-htly less' than-the full diameter of the: side walls of the sheave.

Where it is desiredthatthe sheave have a c'on siderab'ly smallerefiective "pitch diameter for'operation of the-belt flg'the sheavemaybeassembled' with the spacer'rings fll8, fll!) disposetl be twegntthe dianinner portionsof-the side-walls Hi6;- I'M; and the parts clamped'toget'her by the bolts-H4 passing through theapertures iii the-sidewalls, the spacer rings andtlie clamping late I13; airsheave thusassembled being-designated as-J35i1iin Fig.9.

With the sheave 35 assembled as indicated an Fig: 8; Landthe:torsionalrstrasinrof thespring '92 suitably adjusted,throughithevratchet Iiead 'HS, to yieldlngly force the hanger: 91hdmiznvwtrlily to cause the idler 'pulleyifll zitcrzbear in forcibla butyielding; manner on the inner surfacev 0f the driving. belt 34 1 anddistort: the. belt: tmany'position between that: shown. in dottedJineszarndfithat shown in full:lineszin;Eig. :11', the; drive, ing thatthe shaft 36: is driven at a :speed of Z850 R. P. M;, is capable ofcausing the'cylinder"shaft to be operated at any speed betweena-ma'ximurn of approximately 1700 R. .P; M;- andtaminimum ofapproximately '850 .P. M.-, by merelyl-adjustzingthe side Wall Mi ofthesheavei32; through suitable operation of the actuating; crank 69attthe grainwarmsfiie fofi thez'housing 3' H; ttdt'producei-an efientiiet pitchndimeterforrthersheairef 32 10am:- sponding'to thedesiiednyllnderspeed; ImFigzll'; partsiofrlthe drive-91min full :linesinlthe positionsmssmned when-the cylinderisli'aiftiisdiivenwtlitshighesti'speefi;and thepartsiiaisishbwn in dotted lineszintheipesitions assumediwh'emthe cylinder shaft is drivenrat'itsilowestrspeedz whenzitzis desired lto threshim'aterial, :or underconditions;srequiring ian efficient cylinder: speed lessttlian 1850:R;.-B." ,sthe lowestspeed assumed tmug attainable through tne use ofthe sheave 35'; when: assembled as shown in Eig;-8, andiwith the'shaitwboperating atlabo:R.-P; M2, this sheave is'zliiss'embledandi reassembledin theiform shown in" Fig, '9; thus :affording an effective pitch dia-meter;:when using: the same belt Ml equal to' ap proximatelymne-ha'lfof the effective pitchrdiam eter; (if-the: sheave' 35"- when assembled;as: shown iniFigQ 8;

With the sheave 35c in-use, it: maybe d'e sirable tominerease the"torsional strain on= the spring-'92,:soas=to increaserthe eflectiverangeoi operative positions of:- the idler pulley 81. Any necessaryadjus'trnent can be made through the rat'ciiet adjusting r'h'andle 98;on release of the latch 11H; Then; with thesheave 35*a-i'driven-by theshaft 3 6; operating at its normalassumed speedier: 850 R. Pl Mg tliespeed ofthe cylinder shaftmaybe-'variedifrom a maximum of approximatelyfifio R. R' MLattained whemthe p'arts are the. dotted line"position lindicate d in Fig. 10;to 'acminimum speed: ofapproximately=425 Rt P:M., attained wh'en the partsiare in full lineposition indicated in -Fig gi 10;. such adjustment ofathfei cylimierspeed being accomplished by increasing ."tne pitch: diameter of "thesheave 32 through: suitable: adjustment 1 Off the-- actuating crank69iat the grainward side ofrth'e housing "3 It willlher-apparent thatxthrough the invention disclosed liereinabove; there 'is provided' avery siinplesand economicalam:rugged'variable speed drive: capableofareadily varylng the speed' of the threshing cylinder over awide-:raneeto suitably accommodate? for widely: varying threshingconditions, vand athat-ithe': operator can readily make anwsuch' changesinxspeed lfr'om lazposition at the g rainward side' of the cylinder;shaft and the machine;whereihesis safeifrom:injuryifrommov ing ipartsidfrthe'i machine iandic'an' -readi1ydeterminelthetcydinflrispeefliduring such speed adj ust menti.

ltzshould betunderstoo'd that features of the "invention: disclosedherein 1 have definite utilityin other than the particularapparatus-described; andzthattt'he: inventioniisnot limited to the exactdetails surf-construction showntand described; forobviousmov'difications within the scope of the annexed claimsWilliam-apparent to persons skilled iIiLthe-art;

It-ris claimed and desired:- to:secure' by iIi'etters Batent'z 1. :In: aharvester-'thresher' of the-type including aawhee'leazsupporting frame 1structure having azfbrwardly' extending draft element atthestubblewardiside of lthe machine andsupporting a powera'shaftifon'driving operating mechanisms of ther machine: candt havingaithresher housing mountedionithe'. framerstrueture at the grainwardsideofrthemachineaand provided with a rotatable: threshing cylinderhaving a s'haft mounted in bearings? supported: by the sidewalls-creamthrestier'rhousing, amlta variable": speed drive at theestubblewezrdzrsider: ofxtli'ethresher housing frnm atshafticamfid bysaid supporting: strum ture and driven by said power shaft to thestubbleward end of said cylinder shaft, a device operable from thegrainward side of the machine for adjusting said variable speed drive tovary the speed of said cylinder shaft, said adjusting device comprisinga speed-adjusting actuating element at the stubbleward side of saidthresher housing and cooperative with an adjustable element of saidvariable speed drive, a rotatable operating element mounted at thegrainward side of said machine at a point adjacent the grainward end ofsaid cylinder shaft where the operator may manipulate said operatingelement from a position adjacent said end of the cylinder shaft toadjust the speed of the cylinder shaft while measuring the speedthereof, an operating connection from said operating element to saidspeed-adjusting element to efiect speed-varying actuation thereof, saidoperating connection comprising a reciprocable rod connected at one endin screw threaded relation to said operating element and operativelyconnected at the other end to said speed-adjusting element.

2. In a harvester-thresher of the type including a wheeled supportingframe having a forwardly extending draft frame at the stubbleward sideof the machine and supporting a power shaft for driving operatingmechanisms of the machine, and having a thresher housing mounted on theframe structure at the grainward side thereof, said thresher housingbeing provided with a threshing cylinder having a shaft rotatablymounted in the side walls of the housing, and a variable speed V-beltdrive from a drive shaft driven by said power shaft to said cylindershaft, said drive being located at the stubbleward side of the thresherhousing and including a V-pulley on said drive shaft and a V-pulley onsaid cylinder shaft, one of said pulleys being of variable pitchdiameter type, and a V-belt cooperative with said pulleys, a deviceoperable from the grainward side of the machine for adjusting saidvariable speed drive to vary the speed of said cylinder shaft, saidadjusting device comprising a speed-adjusting actuating element at thestubbleward side of the threshing element and cooperative with a,portion of said variable pitch adjustable diameter sheave, an operatingelement mounted at the grainward side of said thresher housing at apoint adjacent the grainward end of said cylinder shaft where theoperator may manipulate said operating element to adjust the 10 speed ofthe cylinder while measuring such speed on a tachometer held against thegrainward end of said cylinder shaft during operation thereof, and anoperating connection extending trans" vcrsely across said thresherhousin from said operating element to said adjustable actuating elementto effect speed-varying actuation thereof during operation of saiddrive, and a belt tensioning device comprising a supporting bracketmounted in position beneath and extending beyond the stubbleward side ofsaid thresher housing, a shaft mounted on said bracket, an arm pivotallymounted on said shaft, an idler pulley rotatably mounted on said arm ata point removed from the axis of said shaft and disposed in position tobear on the face of said belt to effect tensioning of the latter, atorsion spring surrounding said shaft with one end of the spring bearingagainst said pivoted arm, the other end of said spring being anchored toan element rotatably mounted upon an axis coincident with said shaft,and means for adjusting and releasably holding said anchorage element inposition to provide the desired biasing effect of said spring on saidpivoted arm to cause the latter to maintain desired tension on said beltover a wide range of speed variation of said drive.

CHARLES J. SCRANTON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,738,552 Abbott Dec. 10, 19291,715,595 Gouldbourn June 4, 1929 1,506,167 Ellwood Aug. 26, 1924 31,982,299 Hapgood Nov. 27, 1934 2,139,397 Wigglesworth Dec. 6, 1938666,804 Harvey Jan. 29, 1901 724,480 Kennedy Apr. 7, 1908 2,314,250Welty Mar. 16, 1943 403,048 Jones May 7, 1889 FOREIGN PATENTS NumberCountry Date 477,837 Great Britain Jan. 3, 1938 OTHER REFERENCES New AllCrop Harvester, Allis Chalmers Mfg. 00., copyright 1936, 1937, pages 12,13, 18, 19, 26, 27, and 30.

